Locking device for securing a backhoe attachment to a carrier lift arm

ABSTRACT

A mounting frame for attaching a backhoe or other implement to a lift arm of a vehicle, such as a compact loader, includes an upright arm on the mounting frame that is positioned ahead of and adjacent to a forward portion of a lift arm of the loader. The upright arm carries a pivoting locking handle at a first pivot and a locking link is pivotally supported on the locking handle on a first pivot pin. The locking link has a second pivot pin that can be moved to be supported in an existing pin sleeve or bushing on the lift arm. The pivot pins on the locking link are positioned so that when the locking handle is moved to a locked position, the line between the axes of the pivot pins on the locking link goes over center with respect to the pivot axis of the first pivot locking handle, and a hook end of the link latches onto a locking projection on the upright arm. The mounting frame is held in a fixed position relative to the lift arm.

BACKGROUND OF THE DISCLOSURE

The present disclosure relates to a locking assembly for securing a backhoe or other implement attachment that is mounted on the front of lift arms of an attachment carrier, such as a compact loader.

Mounting devices for attaching implements, such as backhoes to carrier vehicles are in wide use. In many instances, the implement that is attached is supported on a tilting attachment plate on a loader or carrier through a suitable latching mechanism, and in many cases the attachment mounting frame has cross rails on which the implement is mounted so the implement can move from side to side relative to the longitudinal axis of the carrier.

It is necessary to ensure that the implement mounting frame is securely supported on the carrier. U.S. Pat. No. 4,279,566 shows a backhoe mounting device, as does U.S. Pat. No. 5,004,398. In the case of the '398 patent, the attachment is secured with an over center latch, but the latch secures the backhoe mounting frame to the main frame of the carrier so that the lift arms are not operable to lift the backhoe or other implement.

SUMMARY OF THE DISCLOSURE

A locking assembly for locking or securing a mounting frame of an implement carried on lift arms of a compact carrier vehicle, such as a skid steer loader, a four wheel loader, or a track driven loader onto the lift arms is disclosed. The mounting frame for the implement, which is disclosed as a backhoe, is attached to a standard tilting attachment plate that is conventionally used for mounting implements onto loader lift arms. The implement mounting frame includes an upright portion, as shown an upright support arm or member on at least one side that pivotally mounts a locking handle. A locking link is pivotally mounted on the locking handle and also has a fixed second pivot pin which engages an open end of an existing bore in a bushing or sleeve in the lift arm used in part for mounting a pin for a tilt cylinder for the tilting attachment plate. The locking link preferably is configured to hook over a pin on the upright support to form a latch. The pivots of locking handle and locking link are positioned so when the locking handle is moved to a locked position, the locking link hooks over the pin on the upright support arm and the line between pivot axes of the locking link pivot pins goes over center with respect to the pivot between the locking handle and the upright arm on the mounting frame. This will prevent the mounting frame from moving away from the respective lift arm. The upright arm and thus the implement mounting frame and implement are held against the carrier lift arms and the implement can be raised and lowered with the lift arms.

An aspect of the present disclosure is that the locking link is pivoted on a locking handle that is mounted on an elongated, laterally extending pivot pin fixed to the mounting frame. The locking handle and the attached locking link can be slid outwardly along the elongated pivot pin sufficiently so that the fixed pin on the locking link clears a side of the lift arm. The locking link can be moved to align with existing bushing or sleeve that is for the mounting pin for a tilt cylinder, and the fixed pin on the locking link then can be slid into an open or unused length of the bore of the bushing or sleeve for the tilt cylinder pin. The locking handle can then be pivoted to a locked position and the locking link hook will engage a pin on the upright arm, as shown a portion of the elongated pivot pin for locking lever, and the upright arm of the mounting frame is pulled tightly against the lift arm, as the line between the locking link pivots goes over center with respect to the pivot of the locking handle. The locking handle can be secured in locking position with a separate pin.

The implement mounting frame can thus be attached and removed from the lift arms of the carrier, such as a loader, easily. The backhoe or other implement is secured against the lift arms and the operator can raise and lower the implement as desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side elevational view of an implement carrier having an implement as shown and described, a backhoe, mounted thereon and held in place on lift arms with a locking assembly made according to the present disclosure;

FIG. 2 is a fragmentary sectional view schematically illustrating a support for a mounting frame and a backhoe on a tilting attachment plate of a loader;

FIG. 3 is a front perspective view of the loader or implement carrier of FIG. 1 having a backhoe mounted thereon and utilizing a locking arrangement made according to the present disclosure;

FIG. 4 is a fragmentary, enlarged side view illustrating a locking assembly on a right side of the loader (opposite from FIG. 1) in an unlocked position;

FIG. 5 is a schematic front perspective view of the locking assembly shown in FIG. 4;

FIG. 6 is a fragmentary top front perspective view of a fixed pivot pin on a locking link aligned with and about to be placed into an existing tilt cylinder pin sleeve on a right side lift arm;

FIG. 7 is a rear perspective view showing the locking link of FIG. 6 in place in a tilt cylinder pin sleeve and the locking handle partially released;

FIG. 8 is a sectional view of a tilt cylinder mounting sleeve on a lift arm with a carrier vehicle, showing a pin for mounting a tilt cylinder and a locking link pin in position in the sleeve;

FIG. 9 is a side view of the locking handle and locking link in a mounting frame locked position; and

FIG. 10 is a fragmentary front perspective view showing a pin in place to ensure the locking assembly remains locked.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A carrier vehicle, as shown a compact loader 10, that can be a skid steer loader, a four wheel drive loader, or a track loader, for example, has a frame 12, and wheels 14 for moving the carrier vehicle (called a loader herein) along the ground. The loader 10 has an operator's cab 18, and an engine compartment 20. Hydraulic lift cylinders 22 are used for raising and lowering a pair of lift arms 24 with respect to the main frame 12 in a known manner. The front end portions 26 of the lift arms have a front surface 28, and at the lower ends of the front portions 26 there are pivots 30 that pivotally mount an attachment plate 32, of conventional design, that is tilted about the pivots 30 with tilt cylinders 34. Tilt cylinders 34 are hydraulic cylinders that can be controlled by an operator to extend and retract piston rods to tilt the attachment plate 32.

The hydraulic tilt cylinders 34 are mounted to the respective lift arms (one on each side) with pins 36 that are mounted in sleeves or bushings 38 (see FIG. 8) that are welded in place in the respective forward portion 26 of the lift arms 24. The attachment plate 32 in this form is used for mounting an implement mounting frame 40 in a conventional manner. The mounting frame 40 supports a backhoe 42 (or other implement) for operation by an operator in cab 18, using known controls. The mounting frame 40 will be called a backhoe mounting frame and the implement will be called a backhoe. The backhoe mounting frame as shown, has side plates 44, and cross rails 46 on which the backhoe 42 can be moved laterally relative to the longitudinal axis to the loader 10.

Mounting frame 40 includes upwardly extending portions at the sides of the mounting frame, as shown, upright arms 50 that are fixed to and positioned near the side edges of the mounting frame. The upwardly extending portions or upright arms 50 form part of the backhoe mounting frame. The upright arms 50 are in substantial alignment with the forward portions 26 of the lift arms of the vehicle. The upwardly extending portions or upright arms 50 on the mounting frame may have pads 51 that rest on the front surface 28 of the front portions 26 of the lift arms when the mounting frame is locked in place. The upright arms 50 are used for mounting a locking assembly 53 for securely latching and holding the mounting frame 40 against the front surfaces 28 of the front portions 26. The locking assembly 53 includes a locking link 52, and a locking lever or handle 54.

Referring specifically to FIGS. 4-10, each locking handle is pivotally mounted on an elongated pivot pin 66 fixed to a forwardly projecting flange or gusset 55 forming a part of respective upright arm 50. The elongated pivot pin 66 thus extends laterally out from a side surface of upright arm 50. This description will relate to one locking assembly, but there are two such locking assemblies, one for each of the loader arms for securing the mounting frame. The locking link 52 has a first pivot pin 58 that is rotatably mounted on a sleeve or hub 57 on the locking handle 50 and is held in place on the locking handle with a snap ring 61. Pin 58 is spaced from the pivot pin 66. The locking link 52 also has a second pivot pin 59 at a free end that is fixed to the locking link and is of size and length to fit within the outer end of sleeve or bushing 38 for the tilt cylinder mounting pin, as shown in FIGS. 7 and 8. Pin 36 for the tilt cylinder does not extend for the full length of the sleeve 38, and the pin 59 inserts far enough into the sleeve 38 to adequately support the pin 59 and carry the locking loads. The end of the locking link 52 that is pivoted to the locking handle 54 forms a hook end or offset portion 60 that carries the first pin 58 to provide a latching hook and to properly position pin 58 for the over center action desired.

FIG. 4 illustrates the locking assembly in a fully unlocked position. The locking handle is pivoted forwardly, and the locking link 52 is also pivoted forwardly about pin 58.

The elongated pivot pin 66 that mounts the locking handle 54 and the locking link 52 to the upright arm 50 is of length so the locking handle and the attached locking link can move out laterally sufficiently so that end of the pin 59 will clear the side surface of the lift arm, as shown in FIGS. 5 and 6 and then the locking link 52 and locking handle 54 are both pivoted rearwardly to position pin 59 near bushing 38 as shown in FIG. 6. In FIG. 6, the pin 59 is aligned with the end of the sleeve or bushing 38, and the locking handle 54 has been broken away to show the locking link 52.

The locking handle 54 and the locking link 52 are then slid along the elongated pin 66 back toward the upright arm 50 on the mounting frame, and thus toward the outer side of lift arm front portion 26 so that the pin 59 can be slid into the sleeve or bushing 38 to the position shown in FIG. 8.

The locking handle is also pivoted in counterclockwise direction as shown in FIG. 7 when the pin 59 is inserted into bushing 58. The upright arms 50 may be positioned slightly from front surface 28 of the lift arms.

FIG. 7 illustrates the locking link 52 in a position such that the second pivot pin 59 is inserted into the bore of the bushing or the sleeve 38, and it can be seen that the locking handle 54 is in a partially locked position after having been pivoted rearwardly to align pin 59 with the bore in sleeve 38. The outer end of elongated pin 66 extends out from the locking handle, since the locking handle has been moved toward the upright arm 50 to position the pin 59 in the sleeve bushing 38. The locking link is positioned between the locking handle and the side of the arm 50.

Once the pin 59 and the locking link 52 have been positioned with the pin 59 fully in the sleeve or bushing 38, the locking handle can be moved to its fully locked position shown in FIG. 9. The hook end 60 fits partially around or hooks on the base end of the pivot pin 66 adjacent the side of the upright arm 50 and to the inside of the locking handle 54.

It can be seen that the line between the pivot axes for the pin 59 and the pin 58 forming first and second pivot pins on the locking link, goes over center with respect to the axis of the pin 66 that mounts the locking assembly 53 to the upright arms.

In order to ensure that the locking lever 54 will not disengage or unlock, (the overcenter action is normally enough) the locking handle is pinned to the upright arm 50 as shown in FIG. 10. The locking handle 54 has a locking tab 70 that extends laterally out and mates with the forward surface of the upright arm 50. The upright arm 50 has a tab end 71 that has an opening 71A that aligns with an opening 70A in the locking tab 70. A pin 72, that is held onto the tab 70 with a chain 74, can be inserted into both of the aligning openings, 70A on the tab 70 and 71A on the upright tab end 71 of the locking arm 51. The pin 72 has a spring loaded retaining ring 75 will fit over the upper end of the tab end 71 on the upright arm 50 and thus be held in place. The openings in locking tab 70 and upright tab 71 with a retaining pin through the aligning openings can be used for securing the locking handle in a latched position even if the locking linkage does not go over center when the locking handle reaches its locked or latched position. The securing of the tab 70 and tab portion 71 together also prevents the locking assembly 51 from sliding outwardly on the pin 66, so pin 59 remains in the sleeve 38. Thus, securing the locking assembly to retain the mounting frame on the lift arms can be done with a securing member to hold the locking handle in locked or latched position.

As stated the hook end 60 of the locking link positions the axis of pin 58 at a position so the pivot axes of pins 58 and 59 are oriented properly so that the line between these axes will go over center with respect to the axis of pin 66 when the locking handle is moved to its locked position. Because the locking link 52 is next to the side surface of arm 50, which mounts the pin 66, the hook end can engage and latch on the base of the pin 66, to provide the latching or securing for the upright arm 50. In other words, the hook end 60 of the locking link secures the upright arm 50 in position. The base end of pin 66 also forms a stop for the locking link and locking handle, to prevent the locking link from continuing to move past a desired latched position.

A locking assembly 53 is carried on each of the upright arms 50 and when the mounting frame 40 is placed onto the tilting attachment plate, and tilted rearwardly so that the arms 50 are adjacent the forward surfaces 28 of the forward portions 26 of the lift arms, the locking link can be placed into position in the respective sleeve 38 quickly and easily, and then by merely moving each locking handle to its locked position, the hook ends of the locking links will engage the pins 66 and secure the upright arms and the mounting frame for the backhoe or other attachment in position. No special modifications of the lift arms are needed.

If desired, the pivot for the locking link 52 to the lift arm can be made in other ways, such as using a separate pin or bore on the lift arm.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. 

1. A mounting frame for mounting an implement to a lift arm on a carrier vehicle, comprising a mounting frame having a portion pivotally mountable to the lift arm, an upper portion of the mounting frame positioned adjacent to and forwardly of a lift arm of the carrier vehicle, a locking handle mounted on said upper portion about a first pivot, a locking link having a first end, a first pivot pin pivotally mounting the first end of the locking link to the locking handle, a second pivot pin at a second end of the locking link pivotally mountable to the lift arm, said locking link having a hook portion for engaging a lock projection on the upper portion, said hook portion engaging the lock projection with the lock projection between axes of the pivot pins of the locking link, and said locking handle being movable about the first pivot to a locked position holding the hook portion engaged with the lock projection.
 2. The mounting frame of claim 1, wherein the lift arm of the carrier has a pin bushing, said second pivot pin of the locking link being insertable into the pin bushing on the lift arm with the locking handle in a release position.
 3. The mounting frame of claim 1 wherein the first pivot comprises a main mounting pin extending laterally outwardly from the upper portion and of length to permit the locking handle and locking link to be slid along the main mounting pin outwardly from the upper portion to a position where the second pivot pin on the locking link clears a side of the lift arm of the carrier vehicle.
 4. The mounting frame of claim 3 wherein the first pivot pin is mounted on the hook portion and extending from a side of the locking link opposite from the second pivot pin.
 5. The mounting frame of claim 1, wherein the lock projection comprises a portion of the main mounting pin mounting the locking handle to the upper portion.
 6. The mounting frame of claim 4, wherein the locking link is positioned between the locking handle and a side surface of the upper portion, a base end of the main mounting pin comprising the lock projection, said hook portion of said locking link engaging the base end of the main mounting pin with the locking handle in locked position.
 7. The mounting frame of claim 5, wherein said upper portion comprises an upright arm, said main mounting pin forming said first pivot having a length sufficient to permit the locking handle and locking link to be slid in a direction away from the upright arm to provide clearance for the second pivot pin on the locking link to move relative to a side surface of the lift arm.
 8. A lockable mounting frame for mounting an implement to lift arms of a carrier vehicle, said mounting frame being adapted to be mounted on a tilting attachment plate at outer ends of the lift arms of the carrier vehicle, a locking assembly carried by said mounting frame, said locking assembly being mounted on a upwardly extending portion of the mounting frame and on an outer side of the upwardly extending portion, said locking assembly having a locking handle and a locking link pivotally mounted to the locking handle, said locking handle being pivotally mounted on said upwardly extending portion, and the locking link being movable to a position along a side of one lift arm on which the mounting frame is mounted, a pin fixed on said locking link and insertable into a pin bushing on the one lift arm, said locking link comprising a toggle which moves from a first position with the locking handle in a release position permitting the upwardly extending portion to be spaced from the lift arm, and the locking link being moved to a second position with the locking handle in a locked position, said second position of said locking link creating a force urging the upwardly extending portion toward the lift arm, and a line between the pin insertable into the lift arm and an axis of the pivot between the locking link and the locking handle going over center with respect to an axis of the pivot between the upwardly extending portion and the locking handle.
 9. The lockable mounting frame of claim 8, wherein the locking link has a hook end engageable with a lock projection projecting laterally from the upwardly extending portion of the mounting frame, and moving the lock projection toward the lift arm as the locking handle moves toward its locking position.
 10. The lockable mounting frame of claim 8, wherein there is a stop on the mounting frame engageably by a portion of the locking assembly to limit the amount that the line between an axis of the pin insertable into the lift arm and an axis of the pivot between the locking link and the locking handle can move over center with respect to the axis of the pivot between the upwardly extending portion and the locking handle as the locking handle moves to its locked position.
 11. The lockable mounting frame of claim 10, said stop being engaged by a hook portion formed on the locking link and positioned such that the hook portion prevents movement of the mounting frame away from the lift arms with the locking handle in its locked position.
 12. The lockable mounting frame of claim 10, wherein said stop comprises a portion of a pin forming the pivotal mounting of the locking handle to the upwardly extending portion.
 13. The lockable mounting frame of claim 12, wherein said pin mounting the locking handle to the upwardly extending portion extends laterally from the upwardly extending portion, and has a length such that the locking handle and the locking link can be moved to be spaced from the upwardly extending portion to permit the locking link to clear a side surface of the one lift arm to permit the pin fixed to the locking link to be moved to a position to be inserted into a pin bushing on the one lift arm.
 14. The lockable mounting frame of claim 13 wherein the locking link is positioned between the locking handle and the upwardly extending portion.
 15. A toggle linkage to secure a mounting frame to a lift arm of a carrier vehicle, said toggle linkage comprising a first locking member pivotally mounted on the mounting frame, a second locking member having a first end engageable with a lift arm on which the mounting frame is mounted, said first locking member being pivotally connected to a second end of the second locking member as the first locking member is pivotally moved about the pivotal mounting on the mounting frame to cause the second locking member to exert a force through the first locking member to pull the mounting frame toward the lift arm to a retained position as the first locking member is pivoted in a first direction.
 16. The toggle linkage of claim 15, and a securing member acting to retain the first locking member in a position holding the mounting frame in its retained position.
 17. The toggle linkage of claim 16 wherein the securing member comprises a tab on the first locking member that is secured to the mounting frame.
 18. The toggle linkage of claim 15, wherein said second member second end is pivotally connected to the first locking member about a pivot axis spaced from a pivot axis of the pivotal mounting between the first locking member and the mounting frame, the first end of the second member having a pivot engageable with the lift arm by a pivot connection on the lift arm, and a line between the pivots at the first and second ends of the second locking member going over center with respect to the pivot axis of the pivotal mounting of the first locking member to the mounting frame as the first locking member is moved to a position drawing the mounting frame toward the lift arm, and a stop to limit the amount of movement of the locking members after the line has gone over center.
 19. The toggle linkage of claim 18, wherein said stop comprises a pin forming the pivotal mounting between the first locking member and the mounting frame.
 20. The toggle linkage of claim 19, wherein said second locking member has a hook portion formed adjacent the pivot between the first and second locking members, said hook portion engaging the pin forming the stop to retain the mounting frame from moving away from the lift arm. 